Diagnostic instrument



FIG. 1 is a front perspective view showing a first embodiment of the new design;

FIG. 2 is a top plan view of the first embodiment of the new design;

FIG. 3 is a front elevation view of the first embodiment of the new design;

FIG. 4 is a side elevation view of the first embodiment of the new design, the side opposite that shown in FIG. 4 being the mirror image thereof; and,

FIG. 5 is a rear elevation view of the first embodiment of the new design.

No bottom plan view is provided since the bottom is unadorned.

The broken line showing is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a diagnostic instrument, as shown and described. 